A wire used in wire bonding may behave more like a transmission line as speed increases. As this happens, intrinsic inductance and/or capacitance of an adjacent wire and the wire may cause signal integrity issues as switching of voltages of the wire creates an unwanted voltage alteration on the adjacent wire. A shielding wire may be used in between the wire and the adjacent wire (e.g., the shielding wire may be coupled to a fixed voltages source like VDD or ground).
The shielding wire may run along an entire length of the wire and the adjacent wire. As a result, the shielding wire may be connected to shielding fingers (e.g., junction points where the shielding wire and signal wires may be coupled), which are usually limited in quantity (e.g., because the signal fingers may contribute to a physical size of an integrated circuit). Reserving signal fingers for the shielding wire may increase cost of the integrated circuit (e.g., increase in material cost, heat, etc.).
In addition, as more and more signal fingers are placed on the integrated circuit, the signal fingers move further along a periphery. As a result, the periphery may be bigger and may move farther away from bond pads. This may cause stray coupling between wires. Furthermore, having more of the shielding wire may require additional input/output devices which can also contribute to increased costs of the integrated circuit.